Improvement in valves for steam-engines



JOHN WATSON.

Improvement in Valves for Steam Engines.

Patented March 26, 1872.

' Fig.4.

WITNESSES.

PATENT 'FFICE;

JOHN WATSON, OF TOLEDO, OHIO.

IMPROVEMENT IN l/ALVES FOR STEAM-ENGINES.

Specification forming part of Letters Patent No. 125,105, dated March26, 1872.

Specification describing an Improvement in Steam-Engines, invented byJOHN WATSON, of Toledo, in the county of Lucas, State of Ohio.

This invention relates to means for reversing the steam in reciprocatingengines without link-motion or special eccentric; and is especiallyintended for locomotive and marine engines. The first part of theinvention consists in a peculiar combination and arrangement of ports inthe cylinder, and in a single perforated slide beneath the valve, byshifting which one set of ports may be closed and another simultaneouslyopened, as required, to secure the desired reversal, the same being thusaccomplished at any part of the stroke, and instantaneously orgradually, as preferred.

' The invention consists, further, in arranging such reversing slidebeneath a supplemental valve-seat, by which it shall be relieved ofpressure.

In the drawing, Figures 1 and 2 are vertical longitudinal sections of areciprocating steamengine illustrating my invention, the valve bein gshown in the same position in both figures, and the reversal of thesteam by the reversing slide indicated by arrows. Fig. 3 is a horizontalsection on the planes indicated by the line as m. Fig. 1, andillustrating, by the line 2 a, the plane of said figure and Fig. 2.Figs.

4. and 5 are plans of the supplemental valveseat and reversing slide,the dotted lines indicating the positions of the ports of the latterrelatively to those of the former.

In carrying out my invention Iconstruct a cylinder, A, with thecustomary valve-seats a a, for a double D-valve, B, and with thecustomary exhaust-ports b b terminating in a discharge-neck, C, but ofdouble length. Instead of the common cylinder-passages, I employcompound passages c 0, each leading from two ports, 1 2, on oppositesides of the exhaustportsb b, and at equal distances therefrom. Thecavities d d of the valve B are adapted to unite the ports 1 or 2 withthe exhaust-ports b1), and their ends 0 e to occupy the spaces betweenthe ports.

From the above description it will be apparent that without furtherprovision both ends of the cylinder, unless cut 011', would be open toboth steam and exhaust at the same time.

To control these ports so that only one set of cylinder-ports (1 or 2)shall be fully open at one time, and so as to admit of closing oropening either set at will, I arrange on the valveseats a a a slide, D,with perforations f f and g 9 the former adapted to connect with theexhaust-ports b b, and the latter to open, re spectively, thecylinder-ports 1 and. 2, as illustrated in Fig. 5. To relieve this slidefrom pressure, so as to adapt it to be readily shifted by hand, I coverit with a plate, E, perforated correspondingly with the valve-seats a a,and supported by shoulders h, (Fig. 3,) or their equivalent, which plateforms the valve-seat proper. The slide D, supplemental valve-seat E, andvalve B are inclosed in a steam-chest, F, of proper dimensions, having acollar or aperture, G, for the admission of steam above the valve, andcollars or stuffing-boxes i j through which the "alve-rod H and a rod,I, by which to shift the slide E, extend, the

former to an eccentric and the latter to a handlever. or theirequivalents.

The reversing operation is clearly illustrated in Figs. 1 and 2. Thepiston J is represented.

in Fig. 1 as making its up-stroke, the steam having access to its facethrough portl of the cylinder-passage c and the contiguous perforation gof the slide D, and escaping from its back through port 1 ofcylinder-passage c, perforation g at that end of slide D, cavity d ofvalve B, perforation f of slide D, and exhaust-port b. It is now desiredto reverse the engine. The slide D being relieved of press ure by thesupplemental valve-seat E, is readily shifted by hand to the oppositeend of its space, as shown in Fig. 2. Cylinder-port 1 is now closed andcylinder'port 2 open, that of passage 0, (before steam,) throughperforations gr and f of slide D, and cavity at of valve B, remainingover the same to the exhaust, and that of passage 0, (before exhaust,)through perforation g of slide D, to steam. The flow of steam and thestroke of piston J are consequently reversed, as indicated by thearrows.

The valve B may, if preferred, ride on the reversing slide D, the steampressure being balanced in any suitable manner.

Claims.

What I claim as new herein is scribed, in combination with the describedreversing' slide D and double D-slide-valve B, for relieving the saidslide from pressure, as

set forth.

JOHN WATSON.

Witnesses O. F. ADAMS, RALPH OSBORN.

